This invention relates to a tape reel assembly having, or to have, a length of magnetic tape wound thereon. More specifically, the invention pertains to such a tape reel asssembly which lends itself to use as a removable supply reel of a magnetic video tape cassette in which a takeup reel assembly is permanently mounted for reel-to-reel tape transportation.
Video tape recorders (VTRs) for use with magnetic tape packaged in cassette form have won extensive commercial acceptance. The magnetic video tape cassette houses a supply reel and a takeup reel with a length of magnetic tape having its opposite extremities anchored to both reels. The cassette can be slipped into the VTR for recording or reproduction without threading the tape. Thus the cassette contributes to the ease of handling of the tape and to its protection against destruction when the tape is not in use.
There has been an inconvenience, however, arising from the fact that the video tape cassette of standard design is not so compact in size as can be desired. The cassettes demand a large storage space when their stock increases. It has been no easy task, either, to carry the cassettes from one location to another.
In an attempt to overcome these inconveniences, Japanese Unexamined Patent application No. 62-184677 suggests a magnetic tape cassette having a reel assembly that is readily removable from within the cassette housing together with the tape wound thereon. The supply reel assembly has a reel housing in which a tape reel is rotatably enclosed. The tape reel is mounted in, and dismounted from, the tape cassette together with the reel housing. The removable supply reel assembly has a far less storage space requirement, and is easier to handle, than the cassette itself.
An objection to this known solution is that the removable supply reel is enclosed in its own reel housing. The space requirement of the supply reel would, of course, be appreciably less if it had no housing. Another objection is that the outer end of the tape is not positively retained against the loosening of the tape. The tape end has therefore been easily loosened within the reel housing if the tape reel is revolved within the reel housing as by a finger inserted to the reel hub position. When the supply reel assembly is mounted within the cassette, too, difficulties have been encountered in manipulating the tape for threading and anchoring it to a take up reel hub.